powdery mildew

noun

1
: an ascomycetous fungus (family Erysiphaceae) producing abundant powdery conidia on the host
2
: a plant disease caused by a powdery mildew

Examples of powdery mildew in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Wet leaves could lead to fungal and bacterial diseases, including powdery mildew and blightand leaf spot, says Morton. — Lauren David, Southern Living, 10 Aug. 2026 Sons also shared that mixing cornstarch and water has helped with powdery mildew in her experience. — Farima Ferguson, The Spruce, 10 Aug. 2026 It’s best known as a way to combat powdery mildew, a fungal infection that appears as a white, powdery coating on plant leaves. — Madeline Buiano, Martha Stewart, 10 Aug. 2026 Humid weather and overly dense plants create the ideal conditions for powdery mildew spores to settle on leaves and spread. — Nan Sterman, San Diego Union-Tribune, 1 Aug. 2026 See All Example Sentences for powdery mildew

Word History

First Known Use

1889, in the meaning defined at sense 1

Time Traveler
The first known use of powdery mildew was in 1889

Rhymes for powdery mildew

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Browse Nearby Words

powdery
powdery mildew
powdery scab
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Cite this Entry

“Powdery mildew.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/powdery%20mildew. Accessed 19 Aug. 2026.

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Kids Definition

powdery mildew

noun
: a fungus that is a parasite and produces a large number of powdery spores on the host
also : a plant disease caused by such a fungus

More from Merriam-Webster on powdery mildew

Britannica.com: Encyclopedia article about powdery mildew

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